Efficient extracellular recombinant production and purification of a Bacillus cyclodextrin glucanotransferase in Escherichia coli.

The signal peptide DacD promoted the high-level heterologous extracellular expression of a recombinant CGTase from Bacillus sp. G825-6 with a pET20b(+) vector in E. coli BL21(DE3). A protocol based on starch adsorption enabled a fast and efficient purification of the recombinant enzyme.